Someone who is very sexy and pretty / handsome and is believed to be worthy of having sex with or 'banged' which resulted in the slang word 'bangable'. A person being called 'bangable' is therefore being told that the person want's to have sexual intercourse with them or 'bang' them.

*girl walk's into bar who is very beautiful*
man1: "wow, dude, look at that, she's fucking bangable!"
Man2: "I know dude, I'd bang her any day of the week!"

A way to describe someone who has some quality that makes them sexually irresistible, and who doesn't have some quality that would make having sex with them questionable. It's someone who you wouldn't mind having sex with right then, right there, because of some reason. You don't have to be smokin' hot to be bangable. It can be looks, or intangible qualities like personality or charisma.